Reaktion #4451

Reaktionsgleichung

4-[2-(phenylmethyl)-4-thiazolyl]pyridine-1-oxide

phosphorous oxychloride

→

2-benzyl-4-(2-chloro-4-pyridyl)thiazole

Ausbeute 31.0%

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwas warmed on a steam bath overnight
2. 2
   TemperaturAfter cooling the reaction mixture
3. 3
   Einengenwas concentrated
4. 4
   workup.ADDITIONthe residue treated with an excess of aqueous sodium bicarbonate
5. 5
   SonstigeThe tan precipitate was collected
6. 6
   Filtrationether (75 mL), and filtered through celite
7. 7
   EinengenThe filtrate was concentrated to a total volume of 10 mL
8. 8
   workup.ADDITIONdiluted with hexane (50 mL)
9. 9
   SonstigeThe product which crystallized on standing
10. 10
    Sonstigewas collected
11. 11
    Sonstigedried

Vorschrift

A suspension of 4-[2-(phenylmethyl)-4-thiazolyl]pyridine-1-oxide (1.00 g, 0.0037 mol) in phosphorous oxychloride (10.0 g) was warmed on a steam bath overnight. After cooling the reaction mixture was concentrated and the residue treated with an excess of aqueous sodium bicarbonate. The tan precipitate was collected, taken up in methylene chloride (15 mL) and ether (75 mL), and filtered through celite. The filtrate was concentrated to a total volume of 10 mL and diluted with hexane (50 mL). The product which crystallized on standing was collected and dried to afford 2-benzyl-4-(2-chloro-4-pyridyl)thiazole (325 mg, 31%). mp. 104°-106° C.

Quelle